Table Of ContentLimnological Analyses
Second Edition
Robert G. Wetzel
Gene E. li kens
limnological Analyses
Second Edition
Springer Science+Business Media, LLC
Robert G. Wetzel, Bishop Professor of Biology, Department of Biology, University of Alabama,
College of Arts and Sciences, Tuscaloosa, AL 35487, USA
Gene E. Likens, Director, Institute of Ecosystem Studies, The New York Botanical Garden,
Cary Arboretum, Millbrook, NY 12545, USA
Cover art supplied by R.G. Wetzel.
Printed on acid-free paper
Library of Congress Cataloging-in-Publication Data
Wetzel, Robert A.
Limnological analyses/Robert G. Wetzel, Gene E. Likens.-2nd
ed.
p. cm.
Includes bibliographical references.
Includes index.
ISBN 978-1-4757-4100-1 ISBN 978-1-4757-4098-1 (eBook)
DOI 10.1007/978-1-4757-4098-1
1. Limnology-Field work. 2. Limnology-Laboratory manuals.
I. Likens, Gene E., 1935- II. Title.
QH96.57.AIW48 1990
574.5'2632-dc20 90-36439
The first edition of this volume was published by W.B. Saunders Co. © 1979 W.B. Saunders Co.
© 1991 Springer Science+Business Media New York
Originally published by Springer-Verlag New York, Inc. in 1991
Softcover reprint of the hardcover 2nd edition 1991
All rights reserved. This work may not be translated or copied in whole or in part without the written
permission of the publisher Springer Science+Business Media, LLC,
except for brief excerpts in connection with reviews or scholarly analysis. Use in connection with
any form of information and retrieval, electronic adaptation, computer software, or by similar or dissimilar
methodology now known or hereafter developed is forbidden.
The use of general descriptive names, trade names, trademarks, etc., in this publication, even if the former
are not especially identified, is not to be taken as a sign that such names, as understood by the Trade
Marks and Merchandise Marks Act, may accOI;dingly be used freely by anyone.
Typeset by Thomson Press (India) Ltd., New Delhi.
9 8 7 6 5 4 3 2 1
ISBN 978-1-4757-4100-1
We acknowledge with appreciation the early limnological training
and inspiration provided by David C. Chandler and Arthur D. Hasler
Preface to the Second Edition
The response by both instructors and students to the first edition of Limnological
Analyses, which appeared slightly over a decade ago, has been most gratifying. The
intent then was to provide a series of interrelated field and laboratory exercises on
basic subjects of limnology. Those objectives have not changed. Here we present a
revised, updated, and expanded version.
The 29 exercises examine a broad range of topics concerned with both standing
and running fresh waters. The complex mechanisms controlling the metabolism and
dynamics of biotic populations and communities in aquatic ecosystems require an
understanding of physical and chemical variables. About one-third of the exercises
address the major physical components of lakes and streams, important mineral
nutrients, and organic matter. The remainder of the exercises provide rationale and
methods for quantitative analyses of the biota, as well as some integrated analyses
of whole ecosystems. A few exercises address the effects of human activities on aquatic
ecosystems.
The later exercises usually build on experience gained in the earlier ones. Although
most of the exercises can be performed largely in an intensive afternoon, sometimes
additional time beyond the scheduled classroom hours may be needed. Certain
subjects, such as decomposition, do not lend themselves to simple, short-term analyses.
We urge that exercises requiring more time not be avoided, because the subjects are
of major importance, and we have found them to be particularly informative in our
limnological classes. Often these longer exercises provide an opportunity for more
independent individual or small team projects, with results that may be reported to
the entire class in effective learning experiences.
Each exercise consists generally of a brief introduction to the topic with a statement
of its limnological relevance or importance. We selected methods to illustrate a variety
of problems and how they might be solved. Although the methods presented are
nearly always of contemporary research quality, our intentions were not to provide
a rigorous manual of limnological methods, even though many sections could be and
have been used for research purposes. Certain techniques presented in the book are
not the best available, but they provide an introduction to the subject within the
constraints of time, facilities, and experience of the classroom. Where better methods
are available, we have attempted to provide references to these techniques.
As previously, each exercise provides three or more options in an attempt to
accommodate various time, logistic, and equipment constraints or to allow some
students to pursue a more ambitious course of study. We have been gratified that
students often have pursued aggressively many of these suggested extensions of the
exercises. Wherever possible, we have attempted to combine and integrate field and
viii Preface to the Second Edition
laboratory analyses. However, some options can be performed completely in the
classroom laboratory. Although we consider these options to be the least desirable,
some topics are more appropriately conducted in the laboratory at this level of
instruction. For example, the important and complex subject of hydrodynamics can
be introduced in a most illuminating and enjoyable manner by means of lake model
experiments.
We have expanded the questions at the end of each exercise. We encourage students
to answer as many of them as possible, for they often generate critical evaluations
of the problems being addressed and the efficacy of the techniques being used. The
questions and references provided for each exercise can lead students to explore
further the myriad complexities of freshwater ecosystems.
The taxonomy of dominant aquatic flora and fauna is consistently a source of
frustration both in the teaching of courses in limnology and in the preparation of this
book. The taxonomic backgrounds and experience of students entering an initial
course in limnology are usually diverse. Even superficial keys to common organisms
from bacteria to fish would exceed the length of the present text. In the first edition,
we included a few basic keys to orient students with little taxonomical experience to
major separations. These keys were not received well by systematists and were not
used extensively by students. Therefore, we include only a few rudimentary "starter"
taxonomic keys in this edition, and we recommend that the instructors use general
and regional guides to the taxonomy of the flora and fauna of particular regions. We
cite example references of useful general taxonomic works.
We recognize that it would be difficult to accomplish all of the exercises in this
book in an intensive course in limnology during a single semester. Hopefully our
efforts, however, will assist in reducing the labors in such courses and enhance insights
into the operational integrity of aquatic ecosystems. We found the experiences of
others important to the improvements to this book. We welcome further suggestions
on how the exercises might be improved or expanded.
Our ideas for effective instruction of certain topics had a long and diffuse
developmental history. As a result, we are no longer certain of their exact origins.
Effective teachers in our background certainly contributed at least indirectly to aspects
that appear in some exercises, particularly A.D. Hasler, W.T. Edmondson, G.H. Lauff,
D.C. Chandler, and J.R. Vallentyne. Gordon L. Godshalk read critically the entire
work and offered many helpful suggestions to both the first edition and parts of the
second edition. Constructive criticism and good counsel have been received from
numerous persons, including students as they grappled with the techniques in classes.
Discussions about and suggested revisions to portions of the first and/or second
editions were provided by H.L. Allen, J.R. Barnes, R. Bilby, J. Cole, W.G. Crumpton,
H.W. Cunningham, F. deNoyelles, J.A. Dickerman, J. Eaton, R. Edwards, P. Godfrey,
J.B. Grace, C.A.S. Hall, D.J. Hall, R. Hall, G. Hendrey, M. Mattson, W. McDowell,
J. Meyer, S. Nodvin, D.K. Nordstrom, P.H. Rich, B. Riemann, D.W. Schindler,
J. Sloane, A. Stewart, D. Strayer, R. Walter, A.K. Ward, G.M. Ward, and W. Youngs, Jr.
Special insights were received on specific topics by several individuals, particularly
toward improvements in the second edition. Arthur C. Benke offered great refinements
and improvements to the treatments of benthos. Michael F. Coveney, Clifford Ochs,
and Michael Pace counseled us on our new treatment of bacterial productivity. The
new exercise on predator-prey analyses was guided by the efforts of Kenneth Wagner
and W. Charles Kerfoot. Mark D. Mattson contributed significantly to the revision
of the exercise on the inorganic carbon complex. The exercises on manipulation of
model ecosystems, diurnal changes in stream ecosystems, and effect of sewage outfall
Preface to the Second Edition ix
on stream ecosystems contain input from F.1. deNoyelles, P. Godfrey, C.A.S. Hall,
J. Sloane-Richey, and Raymond Barrett. William D. Taylor helped with facets of
phytoplankton biomass analyses, Kathleen Weathers with inorganic nutrients,
Michael Pace with zooplankton feeding, Nina Caraco with whole ecosystem analyses,
Jonathon Cole with decomposition, and Robert E. Moeller with paleolimnological
analyses. Anita J. Johnson prepared many of the final figures. Phyllis Likens provided
invaluable assistance with proofreading. We gratefully acknowledge the assistance
of these and other persons that have encouraged us with this effort. The final
responsibilities for the contents, however, rest with us.
Robert G. Wetzel
Gene E. Likens
Contents
Preface to the Second Edition vii
EXERCISE 1
Lake Basin Characteristics and Morphometry
EXERCISE 2
Light and Temperature 15
EXERCISE 3
Physical Characteristics: Lake Models 31
EXERCISE 4
The Heat Budget of Lakes 43
EXERCISE 5
Morphology and Flow in Streams 55
EXERCISE 6
Dissolved Oxygen 69
EXERCISE 7
Inorganic Nutrients: Nitrogen, Phosphorus, and Other Nutrients 81
EXERCISE 8
The Inorganic Carbon Complex: Alkalinity, Acidity, CO2, pH, Total
Inorganic Carbon, Hardness ........... . 107
EXERCISE 9
Organic Matter 129
EXERCISE 10
Composition and Biomass of Phytoplankton 139
xii Contents
EXERCISE 11
Collection, Enumeration, and Biomass of Zooplankton 167
EXERCISE 12
Benthic Fauna of Lakes 179
EXERCISE 13
Benthic Fauna of Streams 199
EXERCISE 14
Primary Productivity of Phytoplankton 207
EXERCISE 15
Zooplankton Feeding 227
EXERCISE 16
Zooplankton Production 235
EXERCISE 17
Predator-Prey Interactions 241
EXERCISE 18
Enumeration of Fish or Other Aquatic Animals 247
EXERCISE 19
Bacterial Growth and Productivity 255
EXERCISE 20
Decomposition: Relative Bacterial Heterotrophic Activity on
Soluble Organic Matter 271
EXERCISE 21
Decomposition: Particulate Organic Matter 281
EXERCISE 22
The Littoral Zone 291
EXERCISE 23
Experimental Manipulation of Model Ecosystems 301
EXERCISE 24
Diurnal Changes in a Stream Ecosystem:
An Energy and Nutrient Budget Approach 315
